1. Field of the Invention
The present invention relates to sensors, and more particularly to sensors for detecting vibrations such as in gas turbine engines.
2. Description of Related Art
A variety of sensor devices are known for detecting and monitoring vibrations. Piezoelectric sensors have often been used for this purpose. However, certain applications may preclude the use of piezoelectric sensors due to harsh conditions. For example, use of piezoelectric sensors in a gas turbine engine can be limited if the operating conditions are severe enough to shorten the sensor life, diminish the sensor reliability, or otherwise reduce the performance of the sensors. Temperature in particular is an important factor in shortening sensor life. Most sensors either have very short life at high temperatures or cannot operate at all. Additionally, piezoelectric sensors typically have relatively good sensitivity at higher frequencies, but in certain applications there may be a need for sensors to detect lower frequency vibrations than piezoelectric sensors are capable of detecting.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for methods and devices that allow for improved ruggedness and frequency range in vibration sensors. There also remains a need in the art for such methods and devices that are easy to make and use. The present invention provides a solution for these problems.